Improvement in making cast-iron malleable



- nary material.

UNITED STATES PATENT OFFICE.

A. K. EATON, OF NEW YORK, N. Y.

IMPROVEMENT IN MAKING CAST-IRON MALL .EABLE.

Specification forming part of Letters Patent No. 17,561, dated June 16, 1857.

To all whom it may concern:

Be it known that I, A. K. EATON, of the city, county, and State of New York, have invented a new and Improved Mode of Converting (last- Iron into Soft Malleable Iron without Change of Form; and I do hereby declare that the following is a full and exact description thereof.

The nature of my invention consists in the use of oxide of zinc alone or combined with oxide of iron as a decarbonizing agent. Gastings of any desired form of the variety called white cast-iron may be packed in iron boxes, crucibles, or otherwise, in the well-known process for making malleable cast-iron, except that oxide of zinc, or a mixture of oxide of zinc and oxide of iron, is used instead of the ordi- The whole being exposed to a bright-red heat in any suitable furnace, the cast-iron is rapidlydecarbonized at the expense of the oxygen of the oxide of zinc. The metallic zinc thus produced may be allowed to distil over and be collected as pure metal; or it may be reoxidized as it passes off by con tact with heated air and produce white oxide of zinc. The cast-iron after being subjected to this process has the softness, flexibility, and malleability of wrought-iron.

It is not necessary or desirable that the pure oxide ofzinc be used, since the crude oxides, or even the carhonate,may be as successfullyused, and with much greater economy. An elevated temperature readily converts the carbonate of zinc into an oxide of that metal. The oxide of zinc acts much more thoroughly as a decarbonizing agent than oxide of iron, since the volatile metallic zinc passes off as soon as formed, presenting fresh oxide to the surface of the iron, while the oxide of iron (if that substance be used alone) by its reduction surrounds the coating with a fixed envelope of porous iron, which greatly retards the process of decarbonization.

\Vhat I claim as my invention, and desire to secure by Letters Patent, is

The employment of oxide of zinc in the production of malleable-iron castings in the manner specified, so that the articles while under this treatment will have continally presented to them a fresh supply of decarbonizing mate rial.

In testimony whereof I have hereunto sub scribed my name.

A. K. EATON.

In presence of-- HUGH MONEIL, ROBERT STEWART JORDAN. 

